Breast pump



FIG. 1 is a front view of the design for a breast pump;

FIG. 2 is a rear view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a right view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof.

The broken lines shown in the figures depict portions of the breast pumpthat form no part of the claimed design.

CLAIM The ornamental design for a breast pump, as shown and described.